You could try the following:

• Set each layer on/thawed
• Freeze all the other layers,
• Then WBLOCK (for DWG)
• Then in the dialog box that shows up, manually select the objects on screen to create unique single-layer files for each layer you want.

Hi,

In the client's file find objects which are on the Layers you want to have in another drawing, or create a couple of lines on these layers.
Than copy these objects (or lines drawing by you) to clipboard, than paste them to another drawing, than you can erase pasted objects and the Lakers from client's drawing will stay in your drawing.

Maxim